<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
/*++++++++++++++++
 	1.如果加号两边是字符串，加号作用是连接
 	2.如果加号两边是数值，加号作用是计算
 	3.如果加号一边是字符串一边是数值，加号作用是连接*/
			var a = 123;
			var b ="123";
			console.log(a+a+a+b);/*369123*/
			console.log(b+a+a+a);/*123123123123*/
			
			
/*-----------------
 	*/
 			var c = "abc";
 			var d = 123;
 			console.log(c-d);    /*NaN*/
   			console.log(typeof(c-d));   /*number*/
   			
/******************
 	*/
 			var e = "2";
 			var f = 123;
 			console.log(e*f);    /*246*/
 			
/*/////////////////
	*/
   			var g = "123";
 			var h = 123;
 			console.log(g/h);    /*1*/
 			
/*%%%%%%%%%%%%%%%%%取余数
 	*/
 			var j = "123";
 			var k = 2;
 			console.log(j%k);    /*123模以2==>1*/
 			
/*()          改变运算优先级
 	*/
   			var l = 3;
 			var m = 2;
 			console.log(l+m*m)      /*7*/
 			console.log((l+m)*m);	/*10*/
 			
 			
		</script>
		
	</head>
	<body>
	</body>
</html>
